Operating mechanism for retractable members on board aircraft



Nov. 2, 1943. c. R. WASEQIGE OPERATING MECHANISM FOR RETRACTABLE MEMBERS ON BOARD AIRCRAFT Filed Aug. 4, 1939 3 Sheets-Sheet 1 Nov. 2, 1943. c. R. WASEIGE OPERATING MECHANISM FOR RETRACTABLE MEMBERS ON BOARD AIRCRAFT Filed Aug. 4, 1939 5 Sheets-Sheet 2 Nov. 2, 1943. c. R. WASEIGE OPERATING MECHANISM FOR RETRACTABLE MEMBERS ON BOARD AIRCRAFT Filed Aug. 4, 1939 s Sheets-Sheet 5 a' locking device Patented Nov. 2, 1943 OPERATING MECHANISM FOR RETRACT- ABLE MEMBERS ON BOARD AIRCRAFT i i Charles Raymond Waseige, Rueil, France; vested the Alien Property Custodian Application August 4, 1939, Serial No. 288,463

In France August 12, 1938 .16 Claims. (Cl. 24410.2)

The present invention pertains to means for locking the operating mechanisms of retractable members on an aircraft. The retractable members may be in the form of wheels, floats, skids or the like including turrets or cupolas.

Still more specifically the invention relates to the locking devices cooperating withmechanism including bars which are-pivoted on each other and thus form a deformable polygon, and more particularly to those wherein two adjacent sides that are pivoted on each other forma folding strut. r g A further object of the invention is toprovide, in-a collapsible structure including a supporting leg and a folding strut; locking means forming between said two pieces in extended position a brace increasing the stiffness of the structure and assisting. the legin resisting the stresses transmitted by the landing wheel or the like. By. way of examples'there are illustrated in theannexed drawings some embodiments-of my invention as applied to the particular case of a retractable landing gear including a folding strut.

In the drawings: i Fig. 1 is a diagrammatic side view of a landing 8 Fig. 2 is a corresponding plan view; g Fig. 3 shows partly in section, on alarger scale,

ing position Figs. 4 and 5 arerespectively sections along the an'enlarged scale a detail of embodiment and shows diagrammatically an arrangement for anelectricalcontrol ofthe locksition; 1 l

1 Fig. 7 is a view on a larger scale of a part of Fig. 6; i I Y for the landing gear inits landing device, for the landing gear in its landing po- Fig. "8 is a View of fa locking device for the along line IXIX of 8,

7 ing 6.

upper end on a fixed pin 4 of the aircraft. At an intermediate point 5 of each leg 3 is pivoted the end of one of the arms of a folding strut, the other arm of which has its end pivoted on'a fixed pin of the aircraft. The closing of the foldingstrut is effected by means of an actuating device which is shown herein as being of the type described in my prior Patent No. 2,148,972. Said actuating device essentially comprises a housing 6 enclosing a motor and a reducer which drives an outer case 1 capable of rotating on the hous- Said housing 6 is fixed by its ends on the parallel upper arms 8 of two folding struts 1ocated on either side of the wheel I, whereas the two other arms 9 of said folding struts are connected to each otherby a hollow transverse bar I0.

-In the embodiment illustrated in Figs. l-5a a resilient device connects said bar Hi to the case I. Said resilient device herein comprises a compression spring I2 which is arranged transversely of the bar l0 inside same and in the axi of which extends a rod 13 which passes through the bar 10. One end of said rod 13 is shaped like a jaw l4 that embraces a ing l5 of the case 1 and is connected to said lug bya pin I6. Two half-collars 11, which are connected together by bolts embrace the bar 10 in register with the rod I3 and are each provided with a hole through which the rod 13 passes freely. At the opposite end to the jaw M a nut I8 provided with a cylindrical extension is 'screwed on the threaded end of the rod l3.

It is obvious that when the case 1 tends to r0 tate relatively to the housing 6 which is" fixed to the arms 8, the lug l5 pulls or pushes the rod 13 and this stress is transmitted to the bar In.

to the arms 8 about the common axis of the cases 6' and 1, thereby opening or closing thefolding-strut. r

On the other hand, two collars 2|, which are respectively fixed on the legs 3 each carry a bar 22. These two bars 22 are connected to each other obliquely at their opposite end and forma V-shaped assembly, the apex of which-carries'an engaging head 23. The two bars 22 are braced by an intermediate stay 24 on which is pivoted the end of a rod 25, the other end of which carries a slide 26 lodged in a tube 27 which is pivoted to the centre of the bracing spider for the two legs 3. Inside said tube is a spring 28 which 2 i Y r 2,333,132

biases the slide against an adjustable abutment 29 screwed on the threaded end of the tube 21.

The position of the engaging head is therefore determined by the lengthof the resilient connecting link which is formed by the rod and the tube 21 and is itself adjusted by the position given to the abutment 29.

With the engaging head 23 cooperate two hooks 3| which are placed opposite each other and are pivotally mounted on pins 32 carried by a case 33 bolted on lugs 34 of the case Each hook 3| is urged to pivot by a resilient device 35,

the line of action of which passes on one side or on the other of the correspondin pin 32 according to the position of the hook. Between the opposite tails of the hooks 3| are adapted to engage juxtaposed locking rollers 36 which prevent any swinging of the hooks 3| in one direction or in the other. Said rollers 33 are carried by an arm which is mounted on a pin 38 and rotates with an arm 39 carrying a roller 43 that co-operates with a cam 4| carried'by the housing 6. The arm 31 is urged by a spring 42 towards the locking position of the hooks 3| by the roller 33.

When the undercarriage is retracted, position shown in chain dotted lines in Fig. 1, the bars 22 bear against a fixed abutment 35 of the aircraft, which keeps them near the legs 3, thereby decreasing the bulk. On the other hand, the cam 4| of the housing 6 is in contact with the 3| from swinging. When the folding formed of the arms 8 and B-is opened by the action of the actuating means 6 and or of the weight of the undercarriage or of any other retracting device, the case 1 rotates on the housing 5 in the direction ,7, and with it the case 33, so that the head 23 engages between-the hooks 3| slightly before the folding strut arms v8 and 9 are completely open. Immediately thereafter the roller leaves the cam 4|, and the spring 42 moves the arm 3i to its locking position. The rollers 361311115 engage between the tails of the hooks 3| and compel them to move away from each other. During this swinging movement of the-hooks 3|, the line of action of each resilient device passes on'the other side of the pivot pin 32 of the'corresponding hook so that same suddenly swings down behindthe head 23 responsive to the action of said resilient device 35. The deformable system is thus triangulated and made iundeformable by the triangulation element 22 which has hooked itself on to, the actual joint of the foldingstrut.

In order to be sure that the locking is suitably effected, the device is adjusted in such amanner that the case 1 still rotates slightly on the housing 6, after the roller has left the cam 5|, to complete the opening of the folding strut. The rotation of the case I on the housing 6 after triangulation of the deformable linkage formed by the elements 3,73 and 9 causes thespring i2 to be compressed, the rod l3 sliding in the direction ]1 through the bar l0. 7

When the case rotates in the opposite direction on the housing 3 in order to retract the undercarriage, a relaxation of the springlZ firstof all occurs, then the rod 13 tends to actuate the bar In and close the folding strut but. as the locking device prevents this, the spring i2 is compressed, the rod |3 then sliding through the bar III in the opposite direction to f1; meanwhile, the cam 4| encounters the roller, M1 and rocks the lever 31 inorder tounlock the hooks 3 The stressexertedby the rod 13 to close the folding-;

triangulation-element 22 is furthermore provided.

Said device consists in this case of an electric switch '41 which is carried by the stay 24 and is actuated by a rod 48 that slides axially through the head 23. When the engagement is effected, the locking roller 36 pushes said rod 48 endwise and thus operates the switch 41 (Fig. 2) which closes the circuit of an indicating apparatus, a lamp for example, located on the pilots instrument panel.

In the modified embodiment illustrated in Figs. 6 to 9, a lever 39a instead of being actuated by a cam is connected to a rod 49 carried by the core 53 of an electromagnetic contact-breaker 5| (Fig. '7) the movable contact 52 of which co-opcrates with two fixed contacts 53. The energising winding of said electro-magnetic contactbreaker is arranged in a circuit 56 which is connected to a source of electricity not shown. In said circuit are interposed a control switch 51 which is within reach of the pilot and the energising winding 53 of a relay or contact breaker 53 which is interposed in the supply circuit 55 of the motor 6 and is placed at a fixed point on the aircraft. The 'electro-magnetic contactbreaker 5| is in this case provided with two windings and 6| of different resistances. The higher resistance winding 60 is connected to the source of electricity by a conductor 62 and a conductor 33 connected to the circuit 55 at a point located between the electro-magnet 5| and the control switch 51. The other winding 6| of much lower resistance is inserted in a circuit 64 which is in parallel with the circuit 53,63, 62 of the winding 60 and which is provided with a switch 65 carried by the catch bar 22a, and actuated by the sliding rod 48 as the contact breaker 41 in Fig. 2. In the circuit of the winding 60 is interposed a switch 68 which is in this case carried by a branch 8 of the folding strut and co-operates with a projection 69 carried by the other branch 9 in such a manner asto open responsive to the action of said projection 63 when the undercarriage reaches its retracted position.

When the undercarriage is locked in the landing position, the switch 65 is closed and the switch 63 is closed whereas the control button 51 is open. By depressing button 51, by means of a lever adapted to take up several positions/the pilot closes the circuit 62, 63, 63, 53 and also the parallel circuit 64, 6|. The two windings 60 and 6| of the electromagnetic contact-breaker are thus energized and the core 53, by means of the rod 49 and the lever 33a, pulls, the locking member 33a which is retracted, thereby enabling the hooks 3| to be retractedin turn by the action of springs similar to springs 35 shown on Fig. 3. At the same time, the retraction ofthe member 33a allows the rod 48- toslide outwardly by the action of its retracting spring,'thereby opening the switch 65 and cutting-out the flow resistance winding 6|. Towards the end cf:itst travel, that is to say when unlocking has beenrfeffected, the core 53 brings the movable contact'52 into contactwith.the fixed contactsj53land closes ,the circuitpof the winding '58 of the contact-breaker 'ply circuit 55, of the'motor which stops. operatinganother button, but by means of the pels it to open, thereby breaking the circuit 56;

thecontact-breaker 59 opens and breaks the supsame lever which served to push the button 51, thelatter is released, thereby breaking thecircuit of the electromagnetic contact-breaker the undercarriage is lowered by the action of known means which are not shown herein, the switch 68 closes assoon as the lowering, begins, and at the instant when the undercarriage is locked in the, landing position the locking member 36a pushes the rod 48 endwise, thereby closing the switch 65.

In the modified embodiment just described the electric control of the locking device replaces the mechanical control by a cam and a resilient device asdescribed above with reference to Fig. l.

The device for locking the undercarriage in the retracted position is shown in detail in Fig. 8. ,It is similar to'the one described above for lockingv the undercarriage in the landing position. However, thelocking member 361) of the catch rod diifers from the member 36a, mainly by the fact that it is a floating member. The member 361) is provided with aygroove H through which passes a fixed pin 12 and said member is pivoted at 13 on a two-arm lever which is itself pivotally connected: at its ends 15 and T6 to respective levers l"! and 18 which are pivoted at fixed points 19 and ,86 on a frame 8|. .The retracting springs 35b for the hooks Eli) are directly stretched between said hooks and the levers ll, 13. Said floating member 36b can thus swing about the pivot l2,whi1e continuing to keep the hooks substantially in their engaged position. If therefore at the instant of the engagement the catch rod 22b rigidly carried by the bar 9 does not place itself accurately between the two hooks 312) but strikes one-of the hooks 3 lb, it deflects the latter by causing it to swing slightly about its pivot, which movement rocks the fioating member 3511 about itspivot l2 and, through said member, theother hook Nb, and the ;rod 221) thus nevertheless lodges itself in theengag ing position between the two hooks 3H).

For unlocking, the lever I1. is rotated in the,

direction -fz, against the action of the springs 35b thereby causing the member 36b to sli-de on" the pin 12 and releasing the hooks 311 which are then retracted. by the pull of said springs 35b. The rotation. of the lever 11 is obtained by, means of an extension 82 of said lever and the action of a control finger 83 which is pivoted at a fixed point 84 and to which is attached an actuating cable or rod 85. ,This finger 83 can type, to which compressed air is supplied through,

a pipe 93 and which is arranged adjacent the lever 89 which is provided with a cam 94 adapted to open said cock 92 temporarily at the same time as the cable 86 pulls the finger 83.

When the lever 891s in the position I shown in Fig. 10, the whole of the" locking :device" is in locking position; When the pilot brings said lever 89 into the position II,-.he pulls the finger 83 and atthe same time momentarily opens the 5 cook 92, thereby admitting compressed air into the cylinder 88, the piston of which then pushes said finger 83 bygmeans of the rod 81;: The lever 11 isotherefore actuated by two control devices acting simultaneously. By moving the. lever 89 from the position I to the position IIL-the device for locking "the undercarriage in the retracted position remains inoperative whereas the button 5! of Fig. 6 isadepressed thereby causing the device for locking the undercarriage in the landing position to open and the retracting device to be come operative, as previously described. Ii

Of course, the invention is in nowise limited to the details of construction illustrated or described, which have only been given by way of example.

What I claim is: 1 1. In the combination of an operating mechanism for retractable members on aircrafts with locking means to actuate same in the unlocking erating mechanism in a predetermined position,

an electric motor adapted to actuate said operating mechanism, an electric supply circuit for said; motor,'a relay insaid circuit, an electromagnetic contact-breaker, an electric control cir- 3O mechanism and. including a switch in said con-:

trol circuit to break the latter when the-retract tromagnetic contact-breaker including twowindings of different resistances connectedin-p'arallel, said switch being insertedin the circuit of the higher resistance winding, and means responsive to the operation of said mechanism and including a switch in'the lower resistan-cecircuit to. cut the latter when the retractable member is moved out of its projecting position.

' 3. In'the combination of an operating mechanism for retractable members on aircrafts with locking means so arranged as tolock said opcrating mechanism in the retracted position of said member and control means for said locking means, said control means including two sets of control members including a common hand actuated lever arranged to set them operating at the sametime, each of said sets being capable of actuating said locking means to release the operating mechanism. i I

4. In the combination as in claim 3, said controLmeans including a source of energy for energizingone of said sets, the other set being arranged to be energized by a source of energy of a different nature.

5. In the combination as in claim 3, one of said sets comprising means adapted to transmit a movement, said means connecting the hand lever to the locking device, and the other set comprises pneumatically actuatable members, means supplying air under pressure and a valve opercuit, means responsiveto the operation of said 2. In the combination as in claim-l, said -elec-' ablefby said' hand lever and'connected to said supplying means and .said pneumatically actuatable members tocontrol the supply of air pressure thereto;

6. In the combination of an operating mechanism for retractable members on aircraft with locking means so arranged as to'lock said operating mechanism in a predetermined position, motor means adapted to actuate said operating mechanism, a control circuit for said motor means, a relay in saidcontrol circuit, an electro-magnetic contact breaker including a movable core operatively connected to said locking means to actuate same in the unlocking direction when said electro-magnetic contact breaker is energized, and connecting'means between said relay and said contact breaker arranged to operate said relay after the end of the stroke of said 'core required for the release of the locking device. 7 1 '7. In the combination of an operating mech anism for retractable members on aircraft with locking means so arranged as to lo'cksaid operating mechanism in a predetermined position, a motor adapted to actuate said operating mechanism, a control relayfor said motor, a control member for said locking means, an operative connection between said control member and said control relaywhereby said control relay is excited responsive to the release of said locking means, and means for actuating said control member.

8. In a collapsible linkage for a retractable member on aircraft, comprising a supporting leg for said retractable member hinged on the aircraft structure and a folding strut hinged at both its ends on the said structure and on the said supporting leg respectivelya locking device for locking said collapsible linkage in its extended position, said locking device comprising two parts carried respectively-by said folding strut and by said supporting leg, one of said parts. including a headed arm and the other part including catch means arranged to engage the said headed arm when the linkage is in its extended position, whereby said locking ',means forma brace between-said supporting leg and said folding strut in extended position.

- 9. Ina collapsible linkage for a retractable member on aircraftcomprising a supporting leg for said retractable member hingedon the .aircraft structure and a folding strut hinged on both its ends on the said structure and on the said supporting leg respectively, said folding strut being formed by two members connected together by a hinge, a locking: device for locking said collapsible linkage in its extended position, said locking device comprising two parts carried respectively by said hinge and by said supporting leg, one of said parts including a headed arm and the other including catch means arranged to engage said headed arm when the linkage is in its extended, position whereby forming a brace between said supporting leg and; the said hinge.

10. A locking device as claimed in claim,:8,: in

which said part including a headed arm is pivotally carried and spring loaded so as to move into its engaging position automatically.

11. In a collapsible linkage for a retractable member on aircraft comprising two coupled supporting legs, for said retractable member, hinged on the aircraft structure and two coupled folding struts, cooperating with said legs respectively, each of said folding struts being hinged on both its ends on the said structure and on the cooperating supporting leg respectively and being formed by two members connected together by a hinge, the hinges of the two folding struts being coaxial and carried by a common bracing member, a locking device for locking said collapsible linkage in its extended position, said locking device comprising two parts carried respectively by said bracing member and by said legs, one of said parts including a headed arm and the other part including catch means arranged to engage said headed arm when the linkage is in its extended position whereby forming a brace between said legs and said struts.

12. A locking device as claimed in claim 11, in which the said first named part comprises two arms rigidly connected to form a substantially V-shaped assembly and a head carried at the apex of said assembly, the said assembly being pivotally carried and spring loaded so as to move into the engaging position automatically.

13. A locking device as claimed in claim 11, in which said first named part comprises two arms pivotally carried by the respective legs and rigidly connected to form a. substantially- V- shaped assembly and a head carried at the apex, the said arms being spring loaded so as to move into the engaging position automatically.

14. A locking device asclaimecl in claim 11, including further resilient means between said bracing member and the parts of the-struts carrying said last named'member.

15. In a collapsiblelinkage fora retractable member on aircraft, locking means for holding the linkage in one of its extreme positions, said locking means including a head, a pair of hooks mounted to swing upon engagement of said head to maintain the same, said hooks being provided with tails, resilient means loading said hooks and mounted to have their lines of action passing on one side or the other of the swinging axis of the corresponding hooks according to the position of the latter, a movable locking member adapted to engage the tails of the hooks when same are in the locking-position, resilient means urging said locking member towardsits engaging position, and control means for'dis'engaging said locking member 1 a 16. A collapsible linkage as claimed in claim 15, including further motor means for retracting the linkage, a control circuit for said motor means, a relay in said control circuit, an operative connection between said control means and said relay whereby'said relay is operated'responsive to the disengagement of said locking member.

CHARLES RAYMOND WASEIGE. 

